Abstract/Description

Procedures for the electrophoretic detection of isoenzymes and other proteins contained in cassava, beans, and legumes are described. Diagrams illustrating the construction and assembly of equipment required to conduct starch gel and polyacrylamide gel electrophoresis and protein electrophoresis are included. The preparation of the starch and polyacrylamide gels, buffer solutions, and sample solutions is described in detail. Procedures for sample cutting, voltage application time and values, and staining of the main enzymes under study (acid phosphatase, catalase, esterase, fumarase, and peroxidase) are specified. Protein electrophoresis is a much simpler procedure, since protein bands are not influenced by the equipment used in extraction procedures or by the physiological state of the plant material. Total proteins, water-soluble proteins (albumins), salt-soluble proteins (globulins), alcohol-soluble proteins (gliadins), acetic acid-soluble proteins (glutenins), and insoluble or residual proteins can be extracted by these methods. The general procedure for protein extraction consists in mixing 0.4 N sodium chloride and centrifuging until the desired protein is obtained; electrophoresis using basic and acid polyacrylamide gels is described. An analysis is presented of electrophoretic patterns, which can be made by using samples of known identity or through visual intensity measurements. (CIAT)